Constant pressure current collector



Feb. 20, 1968 c. R. NORMAN CONSTANT PRESSURE CURRENT COLLECTOR 2 Sheets-Sheet 1 Filed July 20, 1964 K A H Feb. 20, 1968 c. R. NORMAN CONSTANT PRESSURE CURRENT COLLECTOR 2 Sheets-Sheet 2 Filed July 20, 1964 United 3,57,l35 Patented Feb. 20, 1968 3,370,135 CONSTANT PRESURE QURRENT COLLECTOR Charles R. Norman, South Holland, 111., assignor to Whiting Corporation, a corporation of Illinois Filed July 20, 1964, der. No. 383,662 Claims. (Cl. 191-591) This invention relates to current collectors, and more particularly to a new and improved constant pressure current collector for use with electrically driven overhead cranes and similar industrial equipment energized by an overhead electric trolley wire.

A primary object of the present invention is the provision of a new and improved current collector having a contact insert supported in such a way that the pressure between the insert and the wire is maintained substantially constant during use of the current collector.

Another object of the present invention is the provision of a new and improved current collector wherein the same supports the current carrying wire as the current collector passes along the wire and wherein the current collector carries the insert for vertical yieldable engagement with the upper surface of the wire.

Still another object of the present invention is the provision of a new and improved current collector including a pivotally mounted elongated frame having a pair of rollers for peripheral engagement with the undersurface of the current carrying wire thereby to support the latter at two locations spaced longitudinally of the latter, and also including means for supporting the contact insert for sliding engagement with the upper surface of the wire in a manner wherein the insert is held in vertical yieldable contact with the wire.

Another object of the present invention is the provision of a new and improved current collecting device of simple and inexpensive construction allowing ready removal and replacement of the contact insert.

These and other objects and advantages of the invention will become apparent from the following specification disclosing a preferred embodiment of the invention in the accompanying drawings wherein:

FIG. 1 is a side elevational view of the current collector of this invention;

FIG. 2 is an end view of the current collector as seen looking from right to left in FIG. 1;

F-IG. 3 is a top plan view of the current collector;

FIG. 4 is a section taken along line 4-4 of FIG. 1; and

FIG. 5 is a section taken along line 5-5 of FIG. 1.

Referring to the drawings, the current collector will be seen to include a one piece frame member in the form of a plate being bent or doubled defining a rear wall portion and a front wall portion 11 joined together along their lower edges by a web portion 12. Front wall portion 11, which is of less length than rear wall portion 10, includes oppositely extending integral extensions 14 and 15. Extension 14 and Wall portion 10 include coaxial bores mounting opposite ends of a pin 16 which rotatably supports a roller 17. In like manner, extension 15 and rear wall portion 10 include coaxial bores supporting opposite ends of a pin 18 which rota'tably supports another roller 19. The near ends of pins 16 and 18 (as seen in FIG. 1) are semi-cylindrical in form and their bores in extensions 14 and 15 are correspondingly shaped thereby to prevent rotation of the pins in the frame. Rollers 17 and 19, which are of identical construction, are peripherally grooved for rolling engagement with the undersurface of a current carrying wire 20 which passes between frame wall portions 10 and 11 as the current collector moves along the wire. The grooved rollers act as a guide for the current carrying wire.

Front wall portion 11 includes a pair of integral cars 22 and 23 at its opposite ends, which ears extend at right angles from wall portion 11 toward wall portion 10. Ears 22 and 23 are' of the same size and shape. As noted in FIG. 2, car 23 terminates approximately over the centerline of wire 20.

Wall portions 10 and 11 and ears 22 and 23 define vertically extending guideways for slidably receiving a contact insert 25 in the form of a bar which may be formed of graphite. In other words, portions of confronting faces of wall portions 10 and 11 slidably engage side walls of the insert bar and the inner faces of cars 22 and 23 slidably engage the ends of the insert bar thereby supporting the latter for vertical movement in the current collector frame. Insert bar 25 rides on the upper surface of the current carrying wire in sliding engagement with the latter as the current collector moves along the wire. As noted in FIGS. 2 and 4, the lower surface of the insert is grooved for engagement with the rounded surface of the wire. A

The insert bar is held in vertical yieldable engagement with the wire by means of a pair of springs 27 and 28. Spring 28, which is identical in construction and operation with spring 27, includes a coiled section 29 supported on an car 30 integral with an upstanding wall portion 31 forming a part of rear wall 10. Bar 30 has the end thereof bent to one side (see FIG. 3) thereby to prevent inadvertent separation of the coiled portion of spring 28 from ear 30. Spring 23 includes an upper horizontal run portion 32 received in a notch 34 (FIG. 5) formed in the lower edge of an ear 35 which is integral with rear wall portion 31. Spring 28 further includes a lower horizontal run portion 36 having one end thereof bent in the form of a foot engaging the upper surface of insert bar 25. Spring 28 also includes a vertically extending portion 37 which passes through a looped portion 38 formed on the end of horizontal run portion 32. The upper end of vertical spring portion 37 is bent over to prevent vertical portion 37 from passing through looped portion 38.

As mentioned above, spring 27 is identical in construction with spring 28. Also, the frame rear wall construction for supporting spring 27 is identical but opposite hand with the corresponding rear wall portion supporting spring 23. Accordingly, these parts of the current collector need not be described in detail.

As contact insert 25 wears away during use and thereby decreases in depth or height, springs 27 and 28 open as they continue to urge the insert into contact with the wire until each bent over end of spring portion 37 engages the associated looped portion 38. When the springs open this predetermined amount, they no longer force the contact against the wire. As will be apparent from the drawings, insert 25 will not be completely worn through when the springs are fully opened or expanded. This relationship prevents the contact insert from wearing to such an extent that it would become dislodged by sliding out under ears 22 and 23 and thereby permit the springs to come into contact with wire 20.

Contact insert 25 includes a conductor or pigtail 40 which is attached at one of its ends to the contact and which is connected at its other end to a clip 41. A suitable lead wire (not shown) is connected to clip 41 and extends to the particular electrical component energized by the current conducted by wire 20.

Frame wall portions 10 and 11 include a pair of coaxial bores spaced equidistant from the axis of rotation of the rollers, which bores freely receive a bolt 42. It will be understood that the frame is free to pivot about the bolt as well as move laterally by sliding along the same. Bolt 42 has one end thereof threadingly engaged in an insulating member 43. The bolt head 44 prevents separation of the frame from the bolt. Clip 41 is detachably secured by suitable means to a plate 45 which is apertured for being mounted on the bolt 42 between a pair of washers 46 and 47. A nut 48 threadingly engages the bolt for clamping the washers and plate 45 against one end of insulator 43.

Insulating member 43 is secured to a pair of brackets 50 and 51 by a bolt 52 which passes through coaxial bores in the brackets and is threadingly engaged in a blind bore in the insulating member. Brackets 50 and 51 are bent to clamp against the sides of a square in cross section support member 54. The ends of bracket members 50 and 51 remote from the insulating member are detachably secured together by suitable means such as by a nut and bolt 55, 56.

By way of illustration only, support member 54 may extend from the electrically operated carriage of an overhead crane. Normally, support 54 mounts a plurality of current collectors in vertically aligned relation for collecting current from a plurality of horizontally extending wires which are supported in vertical spaced relation along the idler beam of the overhead crane.

By reason of the unique construction of the current collector of this invention, the current carrying wire is supported at its underside at two locations spaced longitudinally of the wire and the contact insert is supported in vertical yieldably engagement with the upper surface of the wire with the pressure between the insert and the wire being maintained substantially constant throughout the life of the contact insert. Rollers 17 and 19 supported by the frame engage the undersurface of the wire at two locations spaced longitudinally of the wire and thereby support the wire and block off a fixed length of the same as the current collector travels along the wire. The contact insert rides on the upper surface of the wire and is held in yielding engagement with the same by means of springs 27 and 28; the contact insert does not in any way support the wire in the manner of some prior art devices which results in rapid wear of the insert because of the rather high pressure between the latter and the wire due to the insert supporting a portion of the weight of the wire. It will be readily apparent that the contact insert of the current collector of this invention may be readily removed and replaced when desired.

The pivotal support for the current collector of this invention adapts the latter to rock or pivot about the axis of the supporting bolt 42 thereby adapting the current collector to follow the slope of the current carrying wire. The current collector is also adapted to shift laterally by sliding movement along bolt 42. In other words, the current collector readily follows the current carrying wire and does not shift the wire laterally or change the slope of the same which would increase the pressure between the wire and the rollers and contact insert. It should be noted that upon lateral shifting of the current collector substantially all of the lateral shifting forces are taken by the side walls of the grooves in the rollers and not by the contacting face of the insert thereby to minimize wear upon the latter.

It will be realized that by reason of the unique construction of the current collector of this invention, inadvertent separation of the wire from the current collector is most unlikely. This is because the wire is confined above and below by the contact insert and rollers, respectively, and at its sides by the side wall portions of the frame. The wire is restricted against movement away from the rollers not only by the spring biassed insert but also by ears 22 and 23 which extend over the wire. It should also be noted that as the ends of ears 22 and 23 extend over the centerline of the wire, separation of the wire from between the wall portions of the frame is still unlikely even if the contact insert should break and become dislodged from the guideways defined by cars 22, 23 and the confronting faces of wall portions and 11. As pointed out above,

by reason of the construction of the springs the insert is prevented from wearing to such an extent that breakage is likely.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not to be so limited. On the contrary, the invention is susceptible of various forms and modifications without departing from the spirit and scope of the appended claims.

I claim:

1. A current collector comprising, an elongated frame and meeans for supporting the same for movement in a horizontal plane only, a pair of rollers supported by the frame in spaced relation longitudinally of the latter for peripheral engagement with the lower surface of a horizontally extending current carrying wire, said rollers being fixed against vertical movement relative to the frame thereby adapting the rollers to support said wire at two locations spaced longitudinally thereof, means on said frame cooperating with said rollers for confining the wire above and below the same and at both sides thereof, a contact insert extending longitudinally of the frame and having an elongated surface in sliding contact with a substantial portion of the length of the wire which is sup-. ported by and between said rollers, at least a portion of said means on the frame including means engaging said insert bar at its sides and ends thereby mounting the bar for vertical movement relative to the frame, resilient means on the frame engaged with said insert for holding the latter in vertically yieldable contact with the wire, said resilient means serving as the sole mechanical means afiecting the pressure between the wire and said elongated surface.

2. A current collector comprising, an elongated frame, a pair of rollers supported by the frame in spaced relation longitudinally of the latter for peripheral engagement with the lower surface of a horizontally extending current carrying wire, said rollers being fixed against vertical move ment relative to the frame thereby adapting the rollers to support said wire at two locations spaced longitudinally thereof, mounting means supporting said frame for pivoting movement about a horizontal axis equidistant from said rollers and extending transversely of the frame, means supporting said mounting means for horizontal movement only, a contact insert generally in the form of a bar, said frame defining vertically extending guideway surfaces engaging the ends and sides of said insert thereby loosely supporting the same longitudinally of the frame and in vertically yieldable sliding engagement with a substantial portion of the wire supported by and between said rollers, said guideway surfaces which engage the sides of said insert also serving to receive the current carrying wire therebetween, means on the frame cooperating with said last mentioned guideway surfaces and said rollers for confining the wire above and below the same and at both sides thereof, resilient means on said frame engaging said insert for holding the latter in yieldable engagement with said wire, said resilient means serving as the sole mechanical means affecting the pressure between the wire and said insert.

3. A current collector comprising, an elongated frame including a doubled plate defining parallel, spaced vertical walls for receiving a horizontally extending current carrying wire therebetween, which walls are connected at their lower edges by a narrow web which extends longitudinally of the frame, a pair of rollers supported by the frame in spaced relation longitudinally of the latter for peripheral engagement with the lower surface of the wire, said rollers being fixed against vertical movement relative to the frame thereby adapting the rollers to support said wire at two locations spaced longitudinally thereof, said frame cooperating with said rollers for confining the wire above and below the same and at both sides thereof, means supporting said frame for pivoting about a horizontal axis equidistant from said rollers and extending transversely of the frame, a contact insert generally in the form of a bar, said bar being supported longitudinally of the wire in yieldable sliding engagement with the upper surface thereof by sliding engagement of respective sides of the bar with confronting faces of said walls and by sliding engagement of respective ends of the bar with a pair of ears which are integral with one of said walls, resilient means supported by one of said Walls and engaging said bar for holding the latter in yieldable engagement with said wire, said resilient means serving as the sole mechanical means affecting the pressure between the wire and said insert.

4. The current collector according to claim 3 wherein said ears extend across the wire in vertical spaced relation with the latter and wherein said resilient means includes at least one spring, which spring is constructed for expanding a predetermined amount in a vertical plane thereby to cease urging the insert into engagement with the wire before the former wears to such an extent that its vertical dimension is less than the vertical distance between said ears and the wire.

5, The current collector according to claim 3 wherein said ears project from said one Wall toward said other wall and have their ends overlying the centerline of said wire.

References Cited UNITED STATES PATENTS Macrae 19153 Bourgeois 19163.2 X Sharwell 19174 Murphy 19163.2 X Schmunk 19174 X Dean 19174 Covey 19159 X Wanat 19163.2 X Bolden 19174 X Trunko 19174 X Mitchell 19140 Van Hooydonk 191-59 X Milazzo 19153 Myers 19157 Drummey 1915 8 Drummey 19159.1

Great Britain.

ARTHUR L. LA POINT, Primary Examiner.

25 STANLEY T. KRAWCZEWICZ, Examiner. 

1. A CURRENT COLLECTOR COMPRISING, AN ELONGATED FRAME AND MEANS FOR SUPPORTING THE SAME FOR MOVEMENT IN A HORIZONTAL PLANE ONLY, A PAIR OF ROLLERS SUPPORTED BY THE FRAME IN SPACED RELATION LONGITUDINALLY OF THE LATTER FOR PERIPHERAL ENGAGEMENT WITH THE LOWER SURFACE OF A HORIZONTALLY EXTENDING CURRENT CARRYING WIRE, SAID ROLLERS BEING FIXED AGAINST VERTICAL MOVEMENT RELATIVE TO THE FRAME THEREBY ADAPTING THE ROLLERS TO SUPPORT SAID WIRE AT TWO LOCATIONS SPACED LONGITUDINALLY THEREOF, MEANS ON SAID FRAME COOPERATING WITH SAID ROLLERS FOR CONFINING THE WIRE ABOVE AND BELOW THE SAME AND AT BOTH SIDES THEREOF, A CONTACT INSERT EXTENDING LONGITUDINALLY OF THE FRAME AND HAVING AN ELONGATED SURFACE IN SLIDING CONTACT WITH A SUBSTANTIAL PORTION OF THE LENGTH OF THE WIRE WHICH IS SUPPORTED BY AND BETWEEN SAID ROLLERS, AT LEAST A PORTION OF SAID MEANS ON THE FRAME INCLUDING MEANS ENGAGING SAID INSERT BAR AT ITS SIDES AND ENDS THEREBY MOUNTING THE BAR 